51歳からのプログラミング　備忘　Notification IntentService Service コード備忘・まとめ

#Notification　コード備忘
>https://akira-watson.com/android/service.html

<table><td><font color="#999">Notice:<br>startForeground(id,notification)に関して、idが0だとクラッシュ、idが1だと通知機能が無効となる、idが2とかなら通知される、という現象に出会った。巷では0でなければOKとなっていたけれど、僕のコードではそうならなかったので、コードでは2としてます、という注記</font></td></table>

Notification.Builder(context,channelId)　||　NotificationCompat.Builder(context,channelId) のcontextは、AndroidSystemによって通知領域を利用するために必要で、生成されるBuilderオブジェクトの存在期間を超えて存在することはない

**1.API25以前のnotificationコード**
**2.API26以降のnotificationコード**
**3.Android9 Pie以降のmanifest追加コード**
**4.API25以前とAPI26以降を判定するコード**

####1.API25以前のnotificationコード
- builderでコンテンツ設定
- notifyで通知を表示

```java:MainActivity
@Override
protected void onCreate(Bundle savedInstanceState) {
   super.onCreate(savedInstanceState);
   setContentView(R.layout.activity_main);

   NotificationCompat.Builder builder = new NotificationCompat.Builder(this,"channel_id");
   builder.setSmallIcon(R.drawable.notification_icon)
          .setContentTitle("title under 8")
          .setContentText("content under 8")
          .setPriority(NotificationCompat.PRIORITY_DEFAULT);

   NotificationManager manager =(NotificationManager)getSystemService(this.NOTIFICATION_SERVICE);
   manager.notify(0,builder.build());
}
```

####2.API26以降のnotificationコード
- builderでコンテンツ設定
- channelに重要度を設定
- channelを生成
- notifyで通知を表示

```java:MainActivity
@Override
protected void onCreate(Bundle savedInstanceState) {
   super.onCreate(savedInstanceState);
   setContentView(R.layout.activity_main);

   NotificationCompat.Builder builder = new NotificationCompat.Builder(this,"channel_id");
   builder.setSmallIcon(R.drawable.notification_icon)
           .setContentTitle("title over 8")
           .setContentText("content over 8");

   int importance = NotificationManager.IMPORTANCE_DEFAULT;
   NotificationChannel channel = new NotificationChannel("channel_id","name",importance);

   NotificationManager manager =(NotificationManager)getSystemService(this.NOTIFICATION_SERVICE);
   manager.createNotificationChannel(channel);
   manager.notify(0,builder.build());
}
```
####3.Android9 Pie以降のmanifest追加コード
```java:AandroidManifest
<uses-permission android:name="android.permission.FOREGROUND_SERVICE"/>
```

####4.API25以前とAPI26以降を判定するコード
`if(Build.VERSION.SDK_INT >=26)`

```java:MainActivity
String CHANNEL_ID = "channel_id";

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    createNotificationChannel();

    NotificationCompat.Builder builder = new NotificationCompat.Builder(this,CHANNEL_ID);
    builder.setSmallIcon(R.drawable.notification_icon)
           .setContentTitle("title")
           .setContentText("content")
           .setPriority(NotificationCompat.PRIORITY_DEFAULT);

    NotificationManager manager =(NotificationManager)getSystemService(this.NOTIFICATION_SERVICE);
    manager.notify(0,builder.build());
}

private void createNotificationChannel(){
    if(Build.VERSION.SDK_INT >= Build.VERSION_CODES.O){
        int importance = NotificationManager.IMPORTANCE_DEFAULT;
        NotificationChannel channel = new NotificationChannel(CHANNEL_ID,"channel_name",importance);
        NotificationManager manager =(NotificationManager)getSystemService(this.NOTIFICATION_SERVICE);
        manager.createNotificationChannel(channel);
    }
}
```

#IntentServiceとNotification
###1. API16でnotificationを作成
- Android studio targeting API16 でプロジェクト作成
- ServiceはIntentServiceを利用
- Emulator Android4.1　JellyBean　API16で出力

**API Level判定なしのIntentServiceコード**
**API Level判定ありのIntentServiceコード**

####API16のstartServiceコード(MainActivity)
```java:MainActivity

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    Intent intent = new Intent(this,MyService.class);
    if(Build.VERSION_SDK_INT >= 26){
       startForegroundService(intent);
    }else{
       startService(intent);
    }
}
```

####API Level判定なしのIntentServiceコード
```java:IntentService
@Override
public int onStartCommand(Intent intent,int flag,int starId){
    Context context = getApplicationContext();
    NotificationCompat.Builder builder = new NotificationCompat.Builder(context,"id")
            .setSmallIcon(R.drawable.notification_icon)
            .setContentTitle("Title")
            .setPriority(NotificationCompat.PRIORITY_LOW);
    NotificationManagerCompat manager = NotificationManagerCompat.from(context);
    manager.notify(1,builder.build());
    function();
    return START_STICKY;
}

public void function(){
// やりたい処理
}
```
####API LevelありのIntentServiceコード
```java:IntentService
public MyIntentService() {
    super("MyIntentService");
}

@Override
protected void onHandleIntent(Intent intent) {
    NotificationCompat.Builder builder = new NotificationCompat.Builder(this,"channel");
    builder.setSmallIcon(R.drawable.notification_icon)
            .setContentTitle("sample_title")
            .setPriority(NotificationCompat.PRIORITY_DEFAULT)
            .build();

    if(Build.VERSION.SDK_INT >=26){
        int importance = NotificationManager.IMPORTANCE_DEFAULT;
        NotificationChannel channel = new NotificationChannel("channel","name",importance);
        NotificationManager manager = getSystemService(NotificationManager.class);
        manager.createNotificationChannel(channel);
    }

    NotificationManagerCompat compatManager =NotificationManagerCompat.from(this);
    startForeground(1,builder.build());
    compatManager.notify(1,builder.build());
    function();

    return START_STICKY;
}

public void function(){
// やりたい処理
}
```
###2. API29でnotificationを作成
- Android studio targeting API29 でプロジェクト作成
- ServiceはIntentServiceを利用
- Emulator Android9.0　Pie　API29で出力
<br>Emulator Android4.1に出力しても正常に通知された

####API29のMainActivityのコード
```java:MainActivity
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    Intent intent = new Intent(this,MyIntentService.class);
    if(Build.VERSION.SDK_INT >= 26){
        startForegroundService(intent);
    }else{
        startService(intent);
    }
}
```
####API29のIntentServiceのコード
```java:IntentService
protected void onHandleIntent(Intent intent) {
    Notification notification;
    NotificationCompat.Builder builder = new NotificationCompat.Builder(this,"id");
    notification = builder.setSmallIcon(R.drawable.notification_icon)
                          .setContentTitle("title")
                          .setContentText("text")
                          .setPriority(NotificationCompat.PRIORITY_DEFAULT)
                          .build();
    startForeground(2,notification);

    if(Build.VERSION.SDK_INT >= 26){
        int importance = NotificationManager.IMPORTANCE_DEFAULT;
        NotificationChannel channel = new NotificationChannel("id","name",importance);
        NotificationManager notificationManager = getSystemService(NotificationManager.class);
        notificationManager.createNotificationChannel(channel);
    }

    NotificationManagerCompat managerCompat = NotificationManagerCompat.from(this);
    managerCompat.notify(1,notification);
    function();

    return START_STICKY;
}

public void function(){
// やりたい処理
}
```
#ServiceとNotification

#####AndroidManifest.java

```java:AndroidManifest.java
<manifest ...
  <uses-permission android:name="android.permission.FOREGROUND_SERVICE"/>
```
#####MainActivity.java
- API26以上は、startForegroundService(intent)でサービス開始。
- API26未満は、startService(intent)でサービス開始。

```java:MainActivity.java
@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    final Intent intent = new Intent(this,MyService.class);
    Button btn_start = findViewById(R.id.btn_start);
    Button btn_stop  = findViewById(R.id.btn_stop);

    btn_start.setOnClickListener(new View.OnClickListener(){
        @Override
        public void onClick(View view) {
            if(Build.VERSION.SDK_INT >=26){
               startForegroundService(intent);
            }else{
               startService(intent);
            }
        }
    });

    btn_stop.setOnClickListener(new View.OnClickListener(){
        @Override
        public void onClick(View view) {
            stopService(intent);
        }
    });
}
```

#####MyService.java
```java:MyService.java
@Override 
public int onStartCommand(Intent intent,int flags,int startId){
   // 通知コンテンツを設定
   Notification notification;
   Intent intent_pending = new Intent(this,MainActivity.class);
   PendingIntent pendingIntent = PendingIntent.getActivity(this,0,intent_pending,0);
   NotificationCompat.Builder builder = new NotificationCompat.Builder(this,"id");
   notification = builder.setSmallIcon(R.drawable.notification_icon)
       .setContentTitle("Title")
       .setContentText("Text")
       .setContentIntent(pendingIntent)
       .build();

   // API26以上：startForeground(notificationId,notification)で通知表示
   // 通知毎にチャンネルに重要度を設定して、チャンネルを生成
   if(Build.VERSION.SDL_INT >= 26){
      int importance = NotificationManager.IMPORTANCE_LOW;
      NotificationChannel channel = new NotificationChannel("id","nama",importance);
      NotificationManager manager = getSystemService(NotificationManager.class);
      manager.createNotificationChannel(channel);
      startForeground(1,notification);
   }else{
      // API26未満：コンポーネント毎に重要度を設定して
      // notify(notificationId,notification)で通知表示
      NotificationManagerCompat managerCompat = NotificationCompat.from(this);
      notification = builder.setPriority(NotificationCompat.PRIORITY_LOW).build();
      managerCompat.notify(1,notification);
   }
   // ToDo
   Log.d("msg","Mesage");

   //
   return START_STICKY;
}
```